1.Place cabbage in large bowl, cover with iced water, stand 5 minutes until crisp; drain.
2.Meanwhile, make tonkatsu sauce. Bring ingredients to the boil in small saucepan; whisk until smooth. Remove from heat; cool.
3.Pound pork gently with meat mallet. Coat steak in flour; shake off excess. Dip pork in combined egg and the water; coat in breadcrumbs.
4.Heat enough oil to cover pork in medium saucepan or deep-fryer. Cook pork, in batches, turning occasionally, 5 minutes until golden all over (skim oil between batches to remove any crumbs); drain on absorbent paper. Cut pork diagonally into 2cm (¾-inch) slices.
5.Place cabbage on serving plate; arrange pork slices on cabbage. Serve with lemon wedges, mustard and tonkatsu sauce.
Ready-made tonkatsu sauce is also available from Asian food stores. Japanese breadcrumbs are available in two crumb sizes, either size is suitable for this recipe.Note